In short:

Results:

Significant increases in brain volume for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning (nonaerobic) control group!

Questions raised:

Might be interesting to look at observational study of more people over longer periods of time. Presumably there is a limit to how much aging can be slowed/reversed, and an optimal amount of exercise to use.

Insights, lessons learnt:

Aerobic exercise seems to slow down aging in the brain quite a lot. Continue exercise as long as possible to stay sharp.

Highlights:

Fifty-nine healthy but sedentary community-dwelling volunteers, aged 60鈥?9 years, participated in the 6-
month randomized clinical trial. Half of the older adults served in the aerobic training group, the other half of the older
adults participated in the toning and stretching control group. Twenty young adults served as controls for the magnetic
resonance imaging (MRI), and did not participate in the exercise intervention. High spatial resolution estimates of gray
and white matter volume, derived from 3D spoiled gradient recalled acquisition MRI images, were collected before and
after the 6-month fitness intervention. Estimates of maximal oxygen uptake (VO2) were also obtained.

has become increasingly important. Cardiovascular exercise has been associated with improved cognitive functioning in aging humans (3,4). These effects have been shown to be the greatest in higher order cognitive processes, such as working memory, switching between tasks, and inhibiting irrelevant information

Previous research with nonhuman animals has shown that chronic aerobic exercise can lead to the growth of new capillaries in the brain (5,6), increase the length and number of the dendritic interconnections between neurons (7), and even increase cell production in the hippocampus (8). These effects likely result from increases in growth factors such as brain-derived neurotrophic factor (7,9) and insulin-like growth factor (10,11), among others (12).

In one such study (14), we found that older adults with a lifelong history of cardiovascular exercise had better preserved brains than did age-matched sedentary counterparts

Participants in both the aerobic and control exercise groups attended three 1-hour exercise training sessions per week for the 6-month period of the intervention. Compliance in the exercise sessions was excellent, exceeding 85% for all participants.

Older adults who participated in the aerobic fitness training protocol showed average reductions in risk, relative to participants in the stretching and toning control group, for brain volume loss of 42.1%, 33.7%, 27.2%, and 27.3%, in the anterior cingulate cortex (ACC/SMA), right superior temporal gyrus (rtSTG), right middle frontal gyrus (rtMFG), and anterior white matter (AWM) clusters, respectively. We should note that our sample is somewhat smaller than the recommended minimum for risk-reduction estimates, and as such, the risk reduction estimates should be viewed with some caution.